Test D (Code 44): Vent Solenoid Shorted
NOTE:
For TEST "D" pin test connector locations See Fig 1.
NOTE:
Resistance measurements in this procedure check condition of air spring solenoid valve coil and diode. A digital ohmmeter will not pass enough current through diode to check its condition. Use Rotunda Tester (059-00010) or equivalent analog ohmmeter.
- Remove air cleaner assembly and shield protecting air compressor assembly. Disconnect air compressor connector. Inspect connector for damage or corrosion. Ensure wire terminals are located correctly and fully seated. Inspect air compressor assembly connector to ensure it is correctly wired.
- Turn air suspension switch to OFF position. Disconnect module connectors. Turn air suspension switch to ON position. Measure voltage between circuit No. 414 (Orange/Red wire) and ground at harness connector. Meter should indicate battery voltage. Measure voltage between circuit No. 421 (Pink wire) and ground at harness connector. See Fig 1. Meter should indicate zero volts.
- If circuit No. 414 indicates battery voltage and circuit No. 421 indicates zero volts, go to next step. If circuit No. 421 indicates battery voltage and circuit No. 414 indicates zero volts, install circuits in correct terminals. If circuits No. 414 and 421 indicate battery voltage, repair short in circuit 421.NOTE: Repeat SERVICE BAY DIAGNOSTICS under TESTING & DIAGNOSIS to verify repairs.
- Measure resistance between Blue wire and Green wire on compressor assembly connector. Reverse leads and measure resistance again between Blue and Green wires. Meter should indicate 25-35 ohms in one directions and less than 25 ohms in the other. If highest reading is 25-35 ohms, replace control module. If both readings are less than 25 ohms, replace compressor assembly. If Code 44 is repeated, replace control module.